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Monday, October 3, 2011

Observations and Inferences

I've been meaning to share this lesson for a couple of weeks, and I finally got around to uploading my pictures! I've even missed Science Week, but better late than never, right?

The very first science lesson I do each year is about observations and inferences. Since we do much of our learning through investigations and experiments, it's really important for students to be able to make observations and inferences and understand the difference.

We talk first about ways to record observations, and we start making a chart that I'll keep up all year long:

I start by placing a cube taped to an index card in the middle of each table group, with strict instructions not to remove the index card. Each cube has the numbers 1, 2, 3, 4, and 6 printed on the five visible sides.

The kids make as many observations as they can about the cube at their table and record them any way they think best. Some kids make bulleted lists, some draw detailed paragraphs, and some write complete sentences. As the kids share their observations, I record them on the board in two columns:
 

I purposefully don't label my two columns; after we have several ideas on the board, I ask students how they think I grouped their comments. They usually figure out pretty quickly that the list on the left contains things we know for sure because we can see them, while the right column contains ideas about the bottom of the cube that we can't see yet. Then I label the left side "observations" and the right side "inferences," and we finish our chart:


Finally, I let students remove their cube from the index card. Most cubes do, in fact, have a 5 on the bottom, but I always mix in one that has a star or smiley face instead. We wrap up the lesson by having a quick conversation about how scientists make inferences to the best of their abilities by looking for patterns, and usually patterns are predictable. However, there's always the possibility of inferences being not quite accurate, and that's why scientists are always looking for new and more accurate ways to make observations.